For our final design, we decided on a mechanism that uses a system of connecting links to mechanically couple the vertical motion of the four-bar rocker to the clamping motion of the claw. As the rocker moves through its range of motion, a secondary linkage transmits this motion to a sliding T-bar within the claw assembly. This converts the rotational motion of the rocker into linear motion of the slider, which in turn actuates the opening and closing of the claw jaws.

Connecting Rods to Combine Motions

image-20260426-004516.png

 

Solidworks Assembly

image-20260426-003636.png

Assembly

IMG_0505.jpegIMG_0517.jpeg

Final Design

IMG_0533.jpegIMG_0538.jpegIMG_0537.jpeg

Our final product consisted of the 4-bar crank system, the claw mechanism, the base, and the integrated circuits that powered the motor to actuate our robot arm.

In terms of circuits, we used an Arduino, a breadboard, a 9V battery, and a 13-kg servo motor

Updated BOM:

Part

Purpose

Quantity

Price

Source

2 ft x 2 ft Acrylic Sheet 6mm

Used for double rocker links and claw arms

1

32.00

TIW

Rotary Bearing

Reduce friction at joints

8

Excluded from BOM

TIW

Bearing Shafts

Connect links

8

Exluded from BOM

TIW

Plastic Gear Set

Used for claw mechanism

4

6.91

https://www.amazon.com/Plastic-Spindle-Assorted-Aircraft-3-17MM/dp/B075QYB66V/ref=sr_1_33?dib=eyJ2IjoiMSJ9.rd3Q4coQN-xK_iVME0RsSTnBPKlOv1wya6YzAMkVHRv8mM3jbPZpXXrtHOcVJOGdLVvyQGaYgAjicYi8lcInydS56uTA6PDMULsp78q1Hrl_5taZ6SpHj7Sem5SFCDimi9RnS_PLtqPHU9zebBRrJXUVfQV-DV7trzLzTNz_24D5qbwhlLcMbfxWPNOTRcKVhsHO-RzXQL-RXY30pSgLMUg85bvDAe8N4qjj1SxZKBfYwd76UX39Uggoq4LbwISbZbVrLxpTB-6hQLN3y_W7Q2ric3eGzLz76CYUU4MdJxM.KSIGFw6HIoBeyys4lvedAYDeiAH4RWWAKulQm4ekKFw&dib_tag=se&keywords=plastic+gear+set&qid=1775455196&sr=8-33

Servo Motor

Actuate double rocker

1

Excluded from BOM

TIW